Elapsed-time electric signal.



F. O. HIRDLER. ELAPSED TIME ELECTRIC SIGNAL.

APPLICATION FILED 001. 1a, 1910.

1,05 1,228. Patented Ja11.'21, 1913.

2 SHEETSSHEBT 1.

' INVENTOR WITNESSES 6'7 EGflZ/dlfil,

/ [I I BY f ATTORNEY F. O. HIRDLER. ELAPSED TIME ELECTRIC SIGNAL.

APPLICATION FILED OCT. 18, 1910.

Patented Ja11.21, 1913 2 SHEET$SHEET 2.

V4 /7 w w zrdler; INVENTOR,

WITNESSES ATTORN EY oFFIcE.

FAIRBANKS C. HIRDLER, OF OKLAHOMA, OKLAHOMA.

ELAPSED- IIME ELECTRIC SIGNAL.

. and useful Elapsed-Time Electric Signal, of

which the following is a specification.

This invention has reference to improvements in elapsed time electric signals, and its object'is to provide a signal means which on the failure of a transmitted signal to elicit a response, will cause a'nothersignal to be produced at another point automatically after the lapse of a. predetermined time.

The present invention is of general application, but is especially adapted for use in connectlon with telephone call signals, particularly those coming from a subscriber and produced at the central station, and for convenience of '(lGSCllptlOD it will be con telephone call signal with the understanding, however, that the general features of the invention are adapted for the production of signals of any kind and for any purpose to which the invention is applicable. It is, therefore, apparent that the invention is not limited to any specific details of construction or arrangements of parts, but that various modifications and changes may be made to suit the different conditions of installation and the circumstances of use, while 'still retaining the salient features of the invention. Furthermore, even in the art of telephony. there are various systems in com-.

mercial use, including the automatic, the

semi-automatic, and the manual, and as the latter has by far the greatest extent of use, the following description will for convenience be directed particularly to the manual system of telephony. Again, practically all the manual systems comprise subscribers sets, subscribers lines, telephone exchange swit'chboards, and operators, such operators being the manual or human element of the system. Since practically the only differences bet-ween various manual systems is in the exchange switch-board which in itself does notatfect the present invention, the following description will be further based upon an exchange switch-board of the Western Electric type '18 being the one in most common use, and, furthermore, the particular showing of the drawings is confined for simplification to a local telephone system, but it will be understood that the in- Specification of Letters Patent.

Application filed October 18, 1910.

Patented Jan. 21, 1913'. Serial No. 587,782

vention is equally well adapted to long distance telephoneasystems.

When a subscriber calls up central, there is a waiting period before an answer comes from the central operator, and this waiting period may be very short, or may be comparatively prolonged, depending upon the conditions then present at the central switchboard. The waiting period which corresponds to the speed of answer of the operator must be kept as low as possible where the telephone company desires to increase business and make money, and such speed of answer must be uniform. As an example, if one company giv'esto its subscribers an average speed of answer onall calls of five seconds with, say, tenper cent. of the an: swers at a maximum of six seconds, and another company gives its subscribers an average speed of answer of four seconds with four per cent. of its calls at twelve seconds, and two per cent. of the calls at twenty seconds, then, althougl-"'the second company gives a faster average service. yet it is evident that the first company gives the better general service.

By the present invention it is commercially and theoretically possible not only to better the-average time as answer to line signals, but, also, to positively reduce delayed answers to line signals to any desired -half times that of the standard average of answering a call.

The present invention will be best understood from a consideration of the following detailed description, taken in connection with the accompanying drawings forming apartigof this specification, in which drawings Figure 1 is a diagram showing so much of a local telephone system as is necessary for the understanding of the present invention,

and also illustrating the present invention' applied thereto. Fig. 2 is a plan View of a switch mechanism comprised in the present invention. F 1g. 3 1s a view similar to that of Fig. 2, but showing another phase in the operation of the'structure. Fig. 4 is a section on the line 4-4 of Fig. 2 Fig. 5 is a section on the line 5-5 of Figra omitting some of the more distant parts seen in Fig. 4.

Referring to 'Figiiihere is shown a sub scribers set 1, a line 4.

going to the balance of the cord circuit.

The armature 12 of the relay 6 is connected to a conductor 13 which is usually grounded at the snitch-board common ground, but in the present invention this conductor leads first through an auxiliary relay 14 and then to ground, indicated at 15.

The parts so far described, with the exception of the relay 1 1, belong to the standard Vestern Electric switch-board circuits and are only referred to for the understanding of the present invention.

The relay 14': has an armature 16 connected on one side by a conductor 17 to one tcrminal of an electro-niagnet 18, the other terminal of which is connected by a conductor 19 to one side of battery 20 which may be a twenty-tour volt battery, the same as the battery 8. The other side of the battery-2O is connected. by a conductor 21. to a contact terminal 22 in the path of the armature 16, so that when the relay 1.41 is energized there is established. a circuit from the armature 16 by way of the conductor 17 to the magnet 18, then by way at the conductor 19 to the battery 20, and from the latter by way of the conductor 21 to the contact 22 and back to the armature 1.6, the magnet 18 being thereby energized.

Branched oil from the conductor 21 is another conductor 23, and branched oft from the conductor 19 is another conductor24, the latter being connected to one side of a relay the other side of which is connect cd by a conductor 26 to one side of a signal light 27 constituting the elapsed time line signal light, and the other side of this lamp 2'? is connected to a conductor 28 which will. be hereinafter referred to.

The magnet 18 1s provided withan armature 29 tast on an arm 30, which latter carried by a pivot 31 shown in Fig. i a boitcarricd by a board 32, but it. will be understood that this showing of the baseboard is simply indicative, and any suitable support may be used.

At the end remote -lrom the pivot pin 31 "the arm is formed with an overhang between which and the body of the arm there extends a pintle 34 forming the journal tor a disk 35' provided with a hub 36, by means of which the disk is centralized be tween the main hody oi the arm 30 which maybe straight and the (n'prhang 33. The

f ee end ot the overhang S3 is in the term of a tooth 37 shown as slightly curved, but such curvature is not mandatory. This tooth is also bent toward the corresponding face of the disk 35, so as to approach quite closely thereto for a purpose which will presently appear.

The disk 35 is made of some suit-able insulating material, such as hard rubber or vulcanized fiber, and carries at its periphery a block 38 of metal, in the path of which is the free end of a brush 39 carried by the arm 80 and normally hearing at the free end on the disk. Projecting from the face of the disk engaged by the arm 39 is a pin 40 in position to engage either side of the tooth 3'7, and this pin is held against. one side of the tooth 37 by a spring 41 made fast at one end to the under face of the disk,'

and at the other end to the arm 30, the said. spring being of the ordinary coiled type and normally under sutticient tension to maintain ,the pin 40 against the tooth 37", but

which spring will permit the turning-of the disk practically one complete rotationu itil stopped by the engagement of the pin 10 with the other side of the tooth 37, the curvature of the latter being such as to then partially embrace the pin. The tooth 37 is bent toward the disk 35 so that it is engaged by the pin 10, which latter, While projecting enough from the face of the disk to engage the tooth 37, will pass under the overhang without engaging the latter. The arm 30 is under the normal control of a spring 41-2 tending to move it away from the magnet 18. but such movement under the action of the spring 12 is limited by a stop pin 4-3 in the path of the arm 30.

lllounted on the base board 32 or other suitable support is a stud let upon which is mounted a! disk 45 of conducting material, and this disk may be r'ast to a gear Wheel 46 driven by a pinion 47, the said gear-wheel and pinion being indicative of any suitable driving moans tor the disk 45, whereby a continual rotative movement at a prcdcter mined speed may be imparted'to thedisk 15. The motor may be a spring motor or an electric motor, or power maybe applied to the disk 4-5 in any other manner, it being the purpose of the present invention to have the disk .45 rotating at all times at a sub stantially "constant speed for a purpose which will presently appear, the only mandatory feature of the structure being that the rotation of the ,disk 45 shall be such as will answer the purposes of the present invention.

When the magnet 1.8 is energized, the arn'iature 29 is attracted and the arin 30 participates in this movement against the action ot the spring 42 until the edge (pf-the disk is brought against the edge of the; disk 45, and as the latter is constantly r0 ntino, rotativc movement is then imparted i 38 is carried by the disk until finally as the energized and the-spring 42 becomes active mal position withithe' stop pinAO in engage ciently to prevent any accidental closure of subscriber at the subscribers station 1 takes ari'nature 16 is attracted intoengagement with the disk and the disk 35 begins to u movement even though the rotative movement of the (llSk 45 continues, and there 1s by way ,ofthe conductor 13 through the to the (alt-L 35, the direction of this rotative movement being such as to carry the pin 40 away from its normal position of engagement with the tooth 37 and the block pin 40 engages the hollow side of the tooth 37 and so arrests further movement of the disk 35, the block 38 is in engagement with the brush 39 and also in engagement with the disk 45, the-block 3S reaching to and being exposed at the periphery of the disk 35. The block 38 therefore acts as a bridging member between the brush 39 and disk 45. The disk 35 ceases further rotative simply produced rubbing contact between the edge of the disk 45 and that edge of the block 38 then engaged by the disk 45. The rotative movement imparted to the disk 45 has caused a winding of the spring 41., so that when the circuit through the magnet 18 is broken and the magnet becomes deto move the arm 30 back into engagement with the stop 43, the spring 41- will then on unwinding return the disk 35 to its norment with the toot-11 37 on the outwardly curved side tl1ereof,'and the block 38 re moved from the disk 45 and brush 39 suitithe circuit through these parts. The nor-v mal position of the parts is shown in Fig. 2, while theiposition ofuthe parts after the disk 35 hja'sfbeen fully acted upon by the disk 45 issliownlinzFigl 3.

Branched oifjfrom the line conductors 2 are other conductors 48 terminating in an elapsed time answering jack 49 which may be engaged by the elapsed time answering cord circuit 50, a part only of which latter is shown, but itmay be of the usual construction. y

In the operation of the system and 'structures described, let it be assumed that the the receiver 01f the hook in the usual procedure calling up central. I Thisfcauses the energization of the relay 6, so that the lamp 4 is made to glow, and at the same time a circuit is established from the battery 8 through the armature 12 of the relay 6 relay 14, the return circuit being by Way that the relay 14 is also en'engized; and its with the contact 22. This establishes a circuitfrom the battery 20 through the magn-et '18 thereby causing a movement of the arm .\3 O,until the disk 35 is in engagement rotate. The speed of the disk 45 and its proportionate sizke wit-hreb n-to the disk I 35 is such that the block 38 is not brought under the brush 39 and in engagement with the disk 45 until a certain time has elapsed. If now the call is answered by'thc regular operator before the block 38 reaches the brush 39, by inserting the plug 9 into the properjack 3, the cut oil relay 7 will operate thereby deenergizing the relays 6 and 14 and cutting out the lamp 4, this causing the decnergizationof the magnet .18 and the return of the arm30 to the normal position under the action of the spring 42, so that the disk 35 is returned to its normal position by the spring 41. Under these conditions the operation of the system is the same as though the improvement were not present. Suppose, however, that the regular operator does not answer before the contact or bridging block 38 reaches the brush 39'and disk 45, then there is established a circuitfrom the battery '20 by way of the conductor 24 through ,the relay 25 which controls the pilot lamp and the latter will be caused to glow, thence the current traverses the conductor 26 to the lamp 27, causing the latter to glow, this lamp being the elapsed time line signal lamp," and from thence the circuit is by'way:,;o'f1'the conductor 28 to the stud 44, disk "'45,'block 38, brush 39, and conductor 23 back-to the battery 20. As soon as the delayed c ll'operator, in front of whoni the lamp [4' comes in, sees the same, she inserts the plug 50 in the jack 49 and completes the call in the regular manner. Theelapsed time line Signal lamp 27 will stay lighted even if the;

delayed call operatorand the regular oper ator do not answer,- since the disk 45 will:

remain.in contact with the block 38 si'inply;..' 10.5

rubbing contact shaft or a single solid shaft may replace ithe. disks and be driven by a single motor. Of course, the stop pin '43 and the pivot 31 maybe made sutliciently long to} be commen to all the rocker arms. These and other like changes are such as would suggest themselves to any engineer installing the system and consequently the invention is. susceptible of such changes without-1 any depart-ure"from the scope of the invention; of -the ground 15 back totheiloattery 8, so- 7 "the drivlngmember 45, a certain prescribed By; properly proportioning the speed of time is given the'regular operator to'answer the c'a1;l,' "and=if' the regular operator fails to answe the' call'within such time, the calli s'au 'tornatically switched to the the call. ,Theglarge majority of calls ar'e,' of course, answered within the-minimum Waiting period byjthe regular. operator and .elapsed'time operator who will. then answer only a comparatively small number are delayed slifiiciently to cause the operation of the elapsed time signal means, whence the elapsed time signal operator may cover a section-of the switch-board controlled by several regular operators, so that even in v large exchanges butfew elapsed time operators are needed. At the same time the average answcnto'line signalsis materially reduced and more prompt and better serviceis rendered the subscribers than can occur :ivith-the usual central station arrangements, the present invention reducing the '25. v I v 1'. In a telephone system including .a call delayed answers to line signals to such predetermined minimum as may be desired.

The elapsed time signal. may, of course, be applied to the pilot lamps only, or to any signal lamps, or to drops in annunciators or to bells and buzzers and the like. In t conditions" where it is desirable to divert an electric current from one translating device to another after the lapse of a. predetermined time.

What is claimed is:-

circuit havinga call signal means at the central station, another call Eircuitat the central station" normally disconnected from the first named call circuit and including a signal means, andmeans at the central station responsive to a call impulse sent throughthe first named signal circuit to establish in the second'named signal circuit electric conditions automatically productive of ,a signal at a predetermined time'after the energization of the first named signal cir cuit. '2. In a telephone system provided with a rail circuit extending from a local station to the central station and there having a call,

signal means, a call circuit local to. the central station and forming an adjunctto the first named call circuit and normally dis connected therefrom, said second named call circuit includinga source of electrical energy, and signal means individual thereto, and means controlledby a signal impulse sent from the local station for causing'the closing of the second-named call'circuit to automatically producea signal a predeterwmined time after the energization offlthe first-named call circuit.

3. An attachment or adjunct for the central station end of a telephone signal system comprising a circuit including a source of current, a signal means, asluggishly op-v erating means for completing said circuit .and automatically energizing the signal means after a predetermined period of time, and means controlled by the first named signal means for setting the sliicgishly'operating means into operation on the receipt of a signal impulse at the central. station over the first named signal circuit,

act, the invention is applicable to all- Ytions and a central station and. asignal tern extendingfrom the local stations to the central station andat the central station insignal for setting the circuit closing means into operation, said last named means being under the control of signal impulses received at the central station.

Ina signal-systemfor telephones, an adjunct to the normal signal circuits comprising a normally open-circuit, a source of current'and anelapsed-time circuit closer in said circuit, a signal means also in said circuit, and another "circuit controlling the elapsed-time"circuiticloser and in turn con. trolled by the normal si nal circuit of the system, said normally open circuit 'ca'usi 7-; the display of a signal on its closure by the elapsed time circuit closer,

6'. Ina telephone system having a signa" circuit extending from local stations to a ital. station, a circuit'local to the central station, a source of current included in said. circuit, a circuit closer forsaid circuit coir,

central station, said circuit closer hcinc' i.

trolled by signal impulses received at the dependent of the normal signal n'icans at said central station, anothcr circuit local to the'centr'al station and including a sin railing means, and a 'sluggishly actin circuit closer controlled by the first named circuit local to the central station for establishing the sec- 0nd named'circuit at the central station and the'display of? a signal'a predetermined line after the display of the signal by the .4 named signal meansat the central station.

7; In a telephone system having local staeluding signal means, a drive means at the central-station capable of constant operation, a circuit'clcseratgthe central station for each local station, 'said'jcircuit closer including .means ca'pa'nleof beingactuatcd by the drive "means": for a predetermined time betore reachmg the circuit closmg position a circuit at the local station for each circuit closer and including a source of current and a signal means individual to said circuit, an operating means for each circuit closer for causing the engagement of the drive and driven means, said operating means being provided with electric actuatingmeans and a circuit including said actuating means, and a circuit closer for said second named cir cuit controlled by signal impulses acting on the signal means. incliulcd in the first named signal circuit and independent of said signal local station, a circuitcloser at the central means.

8. In a telephone system including local and central stations, a signal system including at the central station a signal for each local station, a circuit closer at the central station for each local station, a circuit at the central station controlled by said circuit closer and including a source of current, a rock arm having a-normal tendency in one direction, electro magnetic means included in said circuit and acting on the arm to move it against its normal tendency, a rotatable member carried by the rock arm and provided With a circuit closing member, a driving means for the rotatable member capable of constant, actuation and into engagement with which the rotatable member is moved by the movement of the rock arm against its normal tendency, another circuit local to the central station and including a signal means, and means for the closure of the last named signal circuit by the rotatable circuit closer at a predetermined point in its rotative movement.

9. In a telephone system including local and central stations, a signal system including at the central station a signal'for each rock arm and provided-With a circuit clos-v ing member, a driving means for the rotatable member capable of constant actuation and into engagement With which the rotatable member is moved by the movement of the rock arm against its normal tendency, another circuit local to the central station and including a signal means, and means for the closure of the last named si nal circuitby the rotatable circuit closer at a predetermined point of its rotative movement, the rotatable circuit closer being provided with means for. returning it to normal pbsition avhen' released from engagement with the drive member.

10. In an electric system, a circuit including a 'ource of current, a circuitclosing member izcluded in said circuit, a continui ously moving actuating member, a signal device in the circuit rendered active by the closui' e of said circuit. by the continuously moving device, another, circuit including a signal device and provided iiiit'hmeans for rendering said device active, and means controlled by the energy rendering the second named signal device active for causing the engagement "of the; ircuit closing device in the first-named circuit with theycontinui'o usly moving device for closing the firstnamed circuit a predetermined time interval after the energization of the circuit containing the second-named signal device.

11. In a telephone system having a central station with call receiving circuits and signals therein, another circuit for each call receivingcircuit' local to the central station and including a call receiving signal in position to be responded to by another operator than the one to respond to the first-named signal, said second-named circuit including means for its energizat-ion and an elapsed time circuit closer, means for causing the actuation of the elapsed time circuit closer to close the second-named circuit at the circuit closer, and another circuit closer in the second-named circuit controlled by a call signal received over the first-named circuit to close the second-named circuit at said last named circuit closer and construct- -ed to move to open circuit position when not being acted upon by said call signal.

12. In a telephone system provided With a central station having call receiving signals responsive to impulses sent to the cen tral station from local. stations, a circuit for each call signal and including a call signal individual to said circuit, an elapsed time circuit closer for said circuit, constantly active means for actuating the circuit closer and. normally out of actuating relation thereto, and means controlled by a signal impulse received at the centralstat-ion from a local. station for establishing the active relation of the actuating means with the elapsed time circuit closer to cause a second signal on the failure of respons'eat the central station to the first signal Within a predetermined time.

13. in an electric system, means for the establishment of an electric circuit after a predetermined elapse of time comprising a rock arm, a disk carried thereon, stop means for limiting the movement of the disk to a predetermined extent, a brush carried by the rock arm, a contact member carried by the disk and movable thereby into e gagement with the brush at one limit at the travel of the disk, and a drive member adapted to engage and actuatethe disk and make electric contact with the contact member carried by the disk when the said contact member is in engagement with' the brush.

' ll. In all electric system, means for the estal'ilishment of an electric circuit and means for establishing another electric circuit a predetermined time after the establishment of the first named circuit comprising a rock arm having a normal constraint in one direction,electro-magnetic means con- (rolled by the first named circuit for moving the arm against its normal constraint, a disk carried by the rock arm and having a normal constraint to rotate in one direction,

a contact block carried by the disk, a brush carried by the arm in the path of the con tact block, means for limiting the movement of the disk, and a drive member for the disk in the path of the disk when moved by the electro-magnetic means, said drive member causing a rotation of' the disk against its normal constraint and making electric contact With-the contact block on the disk when the latter is brought into engagement With said driving means.

15. In an electric system, a rock arm, means for constraining the arm in one direction, an electro-magnet formoving' the arm in theother direction, a rotatable disk car ried by the arm, a contact block on the disk, a brush on the arm in the path of the con tact block, co-'acting stop members on the disk and arm for limiting the rotative movement of the disk, constraining means tending' to maintain the disk. at one limit ofits rotat-ive movement, and a rotatable contact member constituting a drive member for the disk and engaging the contact block on the disk when the latter has been moved by the drive member to the limit of its travel in opposition to the constraining means for the disk, the drive member and the driven disk being related to-establish an. electric circuit at a predetermined time after the drive member has be un to actuate the drivenmember.

In testimony, that I claim the foregoing asmy own, I have hereto aiiixed my signature in the presence of two witnesses.

' FAIRBANKS O. HIRDLER. Witnesses:

LAWRENCE T. BERGER, HARRY LEWIS. 

